1. Field of the Invention
The present invention is directed to distributed data communication systems and, more particularly, to intelligent proxies for conducting and enhancing communications between network users and network server hosts in a fashion which is customized for particular users or groups of users applying the technology. Most particularly, the invention is directed to techniques for aiding such intelligent proxies in identifying clients or users so that the proxies may appropriately customize network communications for those users.
2. Background of the Related Art
Typically, a distributed computing network such as the Internet is formed of a number of geographically diverse hosts which are connected to one another, and a number of network users, each of which uses one of the hosts and communicates with other computers on the network through that host (an individual with a personal computer is an example of a single-user host). Although the hosts may be directly connected to the Internet at large so that any information sent to or from a user""s host flows along an unimpeded path to its destination, it is normal and beneficial to interpose a firewall between the host or hosts of a user or group of users and the Internet at large. The firewall performs several functions. Most importantly, it controls the flow of information from the Internet at large to the host. By doing so, the firewall can prevent the introduction of viruses, hacker attacks and the like to the user""s host. It can also provide similar benefits in regulating traffic in the opposite direction, i.e., from the user""s host to the Internet.
A firewall is a complex of functions implemented using a combination of hardware and software, operating to both protect an organization from outside information-related threats and to protect the organization from release of information. An xe2x80x9capplication-level proxyxe2x80x9d is one component of a firewall which is designed to manage the transmission of information relevant to some application or protocol such as HTTP (Hypertext Transfer Protocol, used on the World Wide Web). The basic function of a web proxy is to forward user requests for web documents to their ultimate destinations at various servers on the web and to relay responses back to users. This enables central administration of a single point of transmission through an organization""s firewall.
The decentralized nature of the Internet means that the sources of all information relevant to web users are disparate. As shown in FIG. 1, available information may include vendor-supplied commercial information 50, news 60, opinions 70, ratings 80 and the like. Most web users 90 probably would like to include more sources of information in their activities than they currently do, and would make use of these disparate sources if they were conveniently able to do so. The disparate nature of the needed information, inconvenience of using it, time and cost typically prevent this from happening. Thus, there is a need for the ability to observe, augment, reduce, or otherwise alter general web content for the benefit of a user or group.
Current tools available to users 90 for improving the web experience are inadequate in this respect. Search engines 20 attempt to locate germane documents by examining a large amount of mostly irrelevant information. This is because they are ignorant of user characteristics and hence imprecise. Portals 30 are precise collections of content; however, the available information is determined by the owner of the portal 30, positioning fees paid to the owner and the like. Thus, a user""s choices in a portal 30 are controlled and restricted and may not be relevant. Finally, a branded community 40 is vendor-centric, designed to function only over vendor-enabled sites, and is designed to maximize customer xe2x80x9cswitching costsxe2x80x9d, thus possibly working against the user""s best interests.
The aforementioned Makarios et al. application solves this problem by providing an intelligently augmentable web proxy server which understands the purposeful activities of users and groups which it serves and also enhances their web experience by altering information they receive and send in ways that make it more useful based on its understanding of them. The system includes the web proxy layer, an agent support layer on top of the web proxy layer, and an agent application layer on top of the agent support layer. The agent support layer interfaces with the web proxy layer and includes request agencies which manage a group of personal agents dedicated to analyzing and transforming the web stream of a particular user, and a common agent environment through which agents in the agent application layer can exchange information. In addition to the personal agents managed by the request agency, the agent application layer also includes universal agents which operate autonomously of the activities of users to peruse and understand sources of information on the web based on information gathered by the personal agents.
Although the above provides a workable system, it still requires some method of identifying its clients or users, since the system cannot perform proper customization procedures for them if their identities are not known to the proxy. That is, the system must retain information about a user in order to modify the user""s web interactions on an individual and customized basis.
In a small-scale system it may be possible to assign each client to a dedicated port on the proxy, so that the proxy knows all requests coming from a particular port belong to a given client. However, this technique is too limiting to be of practical use in typical Internet systems where any number of users may selectively connect to any port on the proxy at a given time. Further, it is inadequate in systems where the number of users who can access the proxy outnumbers the number of proxy ports.
The present invention has been made with the above problems of the prior art in mind, and it is an object of the present invention to provide a means by which a web proxy server can establish and maintain state information with a particular web client to, for example, maintain the identity of a user who is making a sequence of web requests to arbitrary servers located anywhere on the web via the proxy.
This object is achieved according to an aspect of the present invention by providing a system and method which implements a series of token exchange transactions similar to those used when passing browser xe2x80x9ccookiesxe2x80x9d between an Internet server and a browser client. Rather than instigating a cookie exchange transaction from the Internet server to store information relevant to the server, according to this aspect of the present invention the proxy cookie is stored on the client side at the behest of the web proxy. To the browser client, the proxy cookie appears to be identical to any regular browser cookie; however, whenever the browser client presents a request for information to the proxy which is to be passed on to the Internet server, the proxy strips the proxy cookie from the request and uses it to identify the originator of the request. Based on this, the proxy can customize and personalize the client""s information request as appropriate and pass it on to the Internet server.